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If similar evolutionary forces maintain intra‐ and interspecific diversity, patterns of diversity at both levels of biological organization can be expected to covary across space. Although this prediction of a positive species‐genetic diversity correlation (SGDC) has been tested for several taxa in natural landscapes, no study has yet evaluated the influence of the community delineation on these SGDCs. In this study, we focused on tropical fishes of the Indo‐Pacific Ocean, using range‐wide single nucleotide polymorphism data for a deep‐sea fish (Etelis coruscans) and species presence data of 4878 Teleostei species. We investigated whether a diversity continuum occurred, for different community delineations (subfamily, family, order and class) and spatial extents, and which processes explained these diversity patterns. We found no association between genetic diversity and species richness (α‐SGDC), regardless of the community and spatial extent. In contrast, we evidenced a positive relationship between genetic and species dissimilarities (β‐SGDC) when the community was defined at the subfamily or family level of the species of interest, and when the Western Indian Ocean was excluded. This relationship was related to the imprint of dispersal processes across levels of biological organization in Lutjanidae. However, this positive β‐SGDC was lost when considering higher taxonomic communities and at the scale of the entire Indo‐Pacific, suggesting different responses of populations and communities to evolutionary processes at these scales. This study provides evidence that the taxonomic scale at which communities are defined and the spatial extent are pivotal to better understand the processes shaping diversity across levels of biological organization. [ABSTRACT FROM AUTHOR]

Recombination is a central evolutionary process that reshuffles combinations of alleles along chromosomes, and consequently is expected to influence the efficacy of direct selection via Hill–Robertson interference. Additionally, the indirect effects of selection on neutral genetic diversity are expected to show a negative relationship with recombination rate, as background selection and genetic hitchhiking are stronger when recombination rate is low. However, owing to the limited availability of recombination rate estimates across divergent species, the impact of evolutionary changes in recombination rate on genomic signatures of selection remains largely unexplored. To address this question, we estimate recombination rate in two Ficedula flycatcher species, the taiga flycatcher (Ficedula albicilla) and collared flycatcher (Ficedula albicollis). We show that recombination rate is strongly correlated with signatures of indirect selection, and that evolutionary changes in recombination rate between species have observable impacts on this relationship. Conversely, signatures of direct selection on coding sequences show little to no relationship with recombination rate, even when restricted to genes where recombination rate is conserved between species. Thus, using measures of indirect and direct selection that bridge micro- and macro-evolutionary timescales, we demonstrate that the role of recombination rate and its dynamics varies for different signatures of selection. [ABSTRACT FROM AUTHOR]

The sex chromosomes have been hypothesized to play a key role in driving adaptation and speciation across many taxa. The reason for this is thought to be the hemizygosity of the heteromorphic part of sex chromosomes in the heterogametic sex, which exposes recessive mutations to natural and sexual selection. The exposure of recessive beneficial mutations increases their rate of fixation on the sex chromosomes, which results in a faster rate of evolution. In addition, genetic incompatibilities between sex‐linked loci are exposed faster in the genomic background of hybrids of divergent lineages, which makes sex chromosomes contribute disproportionately to reproductive isolation. However, in birds, which show a Z/W sex determination system, the role of adaptation versus genetic drift as the driving force of the faster differentiation of the Z chromosome (fast‐Z effect) and the disproportionate role of the Z chromosome in reproductive isolation (large‐Z effect) are still debated. Here, we address this debate in the bird genus Ficedula flycatchers based on population‐level whole‐genome sequencing data of six species. Our analysis provides evidence for both faster lineage sorting and reduced gene flow on the Z chromosome than the autosomes. However, these patterns appear to be driven primarily by the increased role of genetic drift on the Z chromosome, rather than an increased rate of adaptive evolution. Genomic scans of selective sweeps and fixed differences in fact suggest a reduced action of positive selection on the Z chromosome. [ABSTRACT FROM AUTHOR]

Aim: Evaluating the similarity of diversity patterns across micro‐ to macroevolutionary scales in natural communities, such as species–genetic diversity correlations (SGDCs), may inform on processes shaping community assembly. However, whether SGDCs not only hold across communities but also across lineages has never been explored so far. Here we investigated SGDCs across co‐distributed taxa for different spatial components (α, β, γ), and formally tested the influence of dispersal traits on β‐SGDCs. Location: Western Indian Ocean. Time period: 2016–2017. Major taxa studied: Tropical reef fish species with contrasting dispersal traits. Methods: Using double‐digest restriction‐site associated DNA sequencing (ddRADseq) Single Nucleotide Polymorphism data for 20 tropical reef fishes and distribution data of 2,446 species belonging to 12 families, we analysed the correlations between within‐species genetic diversity and within‐family species diversity (i.e., lineage diversity) for the three spatial components (α, β, γ‐SGDCs). We then related the strength of β‐SGDCs per species to proxies of larval dispersal abilities. Results: We detected positive and significant lineage‐based SGDC only for the β component, that is, the families showing the greatest level of species turnover among sites contain the species with the greatest levels of genetic differentiation. We showed that the Monsoon Drift mainly explained the β‐diversity patterns at both intraspecific and interspecific levels. Higher β‐SGDCs were found for species with short pelagic larval duration and weak larval swimming capacity. Main conclusions: Our study reveals a strong correlation between genetic and species β‐diversity, a result explained by the presence of a 'soft' barrier and mediated by larval dispersal processes. This suggests that vicariance and dispersal limitation are major processes shaping β‐diversity patterns from microevolutionary to macroevolutionary scales in tropical reef fishes. [ABSTRACT FROM AUTHOR]

Hybridization is an evolutionary process with wide‐ranging potential outcomes, from providing populations with important genetic variation for adaptation to being a substantial fitness cost leading to extinction. Here, we focussed on putative hybridization between two morphologically distinct species of New Zealand grasshopper. We collected Phaulacridium marginale and Phaulacridium otagoense specimens from a region where mitochondrial introgression had been detected and where their habitat has been modified by introduced mammals eating the natural vegetation and by the colonization of many non‐native plant species. In contrast to observations in the 1970s, our sampling of wild pairs of grasshoppers in copula provided no evidence of assortative mating with respect to species. Geometric morphometrics on pronotum shape of individuals from areas of sympatry detected phenotypically intermediate specimens (putative hybrids), and the distribution of phenotypes in most areas of sympatry was found to be unimodal. These results suggest that hybridization associated with anthropogenic habitat changes has led to these closely related species forming a hybrid swarm, with random mating. Without evidence of hybrid disadvantage, we suggest a novel hybrid lineage might eventually result from the merging of these two species. [ABSTRACT FROM AUTHOR]

This paper focuses on studying and simulating a GaAs1-xPx/Si1-yGey/Ge triple-junction solar cell structure. First, the strain and the bandgap energy associated to the SiGe layer have been studied. The optimal germanium concentration is 0.88 with a strain around 0.45%. Then, the phosphor concentration effect on the strain and the bandgap energy of the upper layer GaAs1-xPx/Si0.12Ge0.88 has been optimized. At room temperature, the optimal output parameter reach Jsc=34.41mA/cm², Voc=1.27V, FF=88.42% and =38.45% for an absorber thickness of 4.5µm and x=0.47, with a strain that doesn't exceed 1.5%. This study has enabled us to design a high-efficiency, low cost 3J solar cell. [ABSTRACT FROM AUTHOR]

In this paper, we report a simulation and investigation of a single In x Ga 1-x N/GaN axial multiple quantum well nanowire (MQWNW) solar cell of radius r = 190 nm and a length of L = 1165 nm. Our results have been shown that 15 In 0.15 Ga 0.85 N (QW) /GaN (barrier) periods is the maximum number that our structure can be supported with an optimal efficiency of about 1.65% achieved with ε = 1.5%. The insertion of MQWs in nanowire permits the growth of In x Ga 1-x N MQWs with high indium concentration of about 50% and ε = 5%. At this indium concentration, the optimal efficiency obtained was 1.70%. Moreover; the structure has been studied with respect to the nanowire radius. In this context, we have shown that the efficiency enhancement achieved through the increase of radius is attributed to the increase of photo-carriers. Study of polarization and proton irradiations has indicated the negative effect of polarization on structure performances and high resistance of III-N semiconductor materials against the radiations, respectively. From these novel structures we can improve solar cell performance for new applications. [ABSTRACT FROM AUTHOR]

• We report the modelling and optimization of a solar cell based on new material using SCAPS software. • A high absorption coefficient was found. • The influence of thickness, temperature, resistances and defects on the different electrical parameters. • A high conversion efficiency was obtained under optimum parameters. • A respectable compatibility has been shown compared with the results of wxAMPS software. Based on several semiconductor research, we have studied one of the new semiconductors, due to its exciting physical proprieties that in turn solve some problems in the photovoltaic's industry. We have divided this work into two parts. The first part, is to study the optical proprieties of ZnSnN 2 , as calculation of the absorption coefficient, bandgap, reflection coefficient, and transmission coefficient. As for the second part, a study of some parameters that affect the efficiency of p-CuCrO 2 (CCO)/ n-ZnSnN 2 (ZTN) solar cell using SCAPS-1D software, and our results are compared with the results of another software (wxAMPS), where results showed great compatibility with the presence of weak uncertainty. We have studied the influence of many parameters such as the thickness of the absorber layer (n-ZnSnN 2), the thickness of the buffer layer (p-CuCrO 2) , the temperature, the series resistance (R s), the shunt resistance (R sh) and the defect density on the performance of ZnSnN 2 solar cells which included in the real device. The photovoltaic parameters have been calculated using AM1.5G solar irradiance at the intensity of one sun, a temperature of 300 K, and considering the flat band condition at the interface. We have been achieving a high-efficiency of η ≈ 22% without defects. Given the characteristics of this new semiconductor ZnSnN 2 , which composed of earth-abundant, non-toxic and inexpensive element, as well as a high absorption coefficient, it can be considered as an alternative for PV and optoelectronic applications. [ABSTRACT FROM AUTHOR]

Abstract In this work, we theoretically investigate the structural dependence of intersubband absorption of InGaAsSb/GaAs single quantum well structures. We begin by analyzing the impact of In and Sb incorporation on the critical thickness, conduction band offset and band gap energy. The first two electron energy levels E 12 and the corresponding wavelength were made for the In x Ga 1− x As 1- y Sb y /GaAs system and are analyzed in detail by solving the Schrödinger equation. Also, we have investigated effects of composition and well width on the intersubband absorption. In addition, the wavelength and absorption coefficient of the ISBT can be adjusted and optimized by changing the composition and the width of the SQW. Finally, strain effects on intersubband absorption and on the peak response wavelength have also been systematically studied. Our study shows that InGaAsSb/GaAs SQW will play a key role in research of electronics and photonic devices in the future. Highlights • Studied the effects of structural parameters on the Intersubband transition of InGaAsSb/GaAs QWs. • Absorption coefficient dependency on the InGaAsSb structural parameters has been investigated. • The effects of these parameters are numerically studied. • Effect of the strain on peak wavelength and on the maximum absorption has been verified. • InGaAsSb/GaAs is a good candidate as a novel material system for optoelectronic intersubband devices. [ABSTRACT FROM AUTHOR]

The aim of this modeling and simulation is to study the influence of the incorporation of nitrogen (N) and aluminum (Al) on the optoelectronic properties of the structure Al x Ga 1-x As 1-y N y /Ge, and then choose the right combination (N, Al) which gives us a better conversational efficiency of the junction(Al x Ga 1-x As 1-y N y /Ge), in this study, we simulated the effect of N and Al on the strain, the band gap, carrier mobility and structure efficiency where we based on theoretical models experimentally validate, It has been shown that the Al concentration slightly affects the stress and the band gap, but it has a significant influence on the incorporation of nitrogen and in a more homogeneous way introducing a dramatic decrease in the band gap what change considerably the absorption, carrier mobility and final yield of the structure. [ABSTRACT FROM AUTHOR]

A pulsed-DC sputtering process at room temperature has been developed for the deposition of the CIGS absorber layer. It uses a single quaternary target and is followed by a high temperature post-deposition annealing process. It has to be particularly noticed that no additional selenium supply was used. The annealed layers have shown a high microstructural quality: micrometric grain size, highly oriented (112) chalcopyrite phase, no phase decomposition and no Cu 2-x Se secondary phase at the surface. The use of such an absorber layer for the fabrication of 0.5 cm 2 solar cells has allowed reaching a conversion efficiency of 11.8% with an open circuit voltage of 558 mV, a short circuit current density of 32.1 mA·cm −2 and a fill factor of 65.8%. [ABSTRACT FROM AUTHOR]

This paper reports simulations of gradual bandgap CIGS absorber and its impact on the characteristics of a solar cell. The bandgap of the CIGS absorber varies linearly and drops from E gmax (at the junction limit) to E gmin (in the vicinity of the rear contact).We introduce an effective absorption coefficient based on this variation. We will demonstrate that this gradual profile contributes to an improvement up to 171 mV of the open circuit voltage V oc of the cell that is linked to the modification of the internal electrical field distribution within the absorber. However, a joint reduction of 1.50 mA/cm 2 of short circuit current density, J sc , is observed. Overall, the conversion efficiency increases from 19.2%, for a uniform bandgap absorber structure, to 24.9% in that case of gradual bandgap. Additionally, we investigate the impact of absorber thickness and temperature on cell characteristics. [ABSTRACT FROM AUTHOR]

Considering the chalcopyrite solar cell fabrication process, the commonly reported substrate bending effect that is observed after thermal process, in a front side halogen lamp-based annealing configuration (Rapid Thermal Annealing –RTA- equipment), has been investigated. We first proposed a simple model explaining the substrate bending shape dependence on the initial stress state within the molybdenum (Mo) layer (free, tensile or compressive). Then, we showed that it is possible to overcome this issue by simply using a reactive (oxygen based) sputtering process for the deposition of the Mo layer. Finally, we showed that using a bilayer structure Mo(O)/Mo allows a more precise control of the flatness of the annealed samples. To understand the mechanisms governing such changes in substrate bending, structural and morphological material changes as a function of oxygen flow have been investigated by using X-ray diffraction and scanning electron microscope imaging, respectively. The elemental distribution throughout the Mo(O)/Mo bilayer structure thickness was also investigated. [ABSTRACT FROM AUTHOR]

This paper focuses on the simulation and optimization of electrical and optical properties such as current density-voltage (J-V ) , external quantum efficiency (EQE) and the photoluminescence spectra (PL) of InSb/GaAs quantum dot solar cell (QDSC). The InSb QDs have been inserted in the intrinsic region of p-i-n GaAs solar cell. Our results have been shown that 30 InSb/GaAs QD layers provide a relative enhancement of 22.35% and 29.30% of the short-circuit current and the efficiency, respectively. With the same number of the QD layers, the absorption range edge of low energy photons has been extended from 900 to 1400 nm. The electrical features obtained for InSb/GaAs QDSC have been compared with those obtained for InAs/GaAs QDSC in goal to show the better structure. The PL spectra has been also compared with experimental result for the same structure. Moreover, the QDSC has been optimized with respect to the thickness of QDs. The optimal conversion efficiency of 10 QD layers is improved from 14.85% to 18.30% by increasing the thickness of the QDs from 5 nm to 20 nm. [ABSTRACT FROM AUTHOR]

In this work, the performance of solar cell based on CdS-n/Cu 2 ZnSnS 4 -p hetero-junction is numerically simulated. The aim of the study is to investigate the influence of thickness, defects density and bandgap energy of absorber layer CZTS and the thickness of the buffer layer CdS of the solar cell on electrical parameters J sc , V oc , FF and efficiency η of the cell. The results of our simulation allowed us to optimize the parameters above mentioned in order to get the best efficiency at the optimal band gap which corresponds to the maximum of the solar spectrum with optimal values of the electrical performances of the cell. This results lead to develop CZTS solar cells with high efficiency and low cost and give a help full indication for fabrication process. [ABSTRACT FROM AUTHOR]

This work deals with the modeling and optimization of the CuInGaSe/CdS based structure for photovoltaic applications. We took into consideration the effect of the gallium concentration and the temperature on the strain, band gap energy, absorption and efficiency of the structure. It has been demonstrated that increasing the gallium concentration increases the ban gap energy, while increasing temperature decreases it. These two parameters vary the efficiency significantly. For x = 30% and T = 300 K, the band gap energy is equal to 1.15 eV with a deformation of 0.5% and efficiency around 20%. We have also found that at this value of the band gap energy the structure absorbs most of the incident photons. Then to achieve a reliable cell based on CuInGaSe/CdS it is adequate to find a compromise between the gallium concentration in the alloy, the temperature and the strain. [ABSTRACT FROM AUTHOR]

In this work, the design and simulation of an GaInP single junction solar cell are presented. The work focuses mainly on the optimization of the PN junction thicknesses of n-base and pemitter cell layers in order to improve the cell conversion efficiency. Besides this optimization, the layers of the cell window AlGaInP and an added buffer AlGaAs were also optimized in term of doping and thicknesses using Atlas tool of SILVACO TCAD. The cell is simulated under the conditions of 1 sun and AM1.5G solar spectrum at 25°C. The simulated GaInP solar cell demonstrates an efficiency (η) of 22.42%. The cell shows different electrical behaviors in terms of short circuit current density (Jsc), open circuit voltage (V∝), fill factor (FF), and external quantum efficiency (EQE). The obtained results are compared with those reported in the literature. Simulation results of the cell are: a Jsc of 18.35 mA/cm2, V∝ of 1.41 V and FF of 86.81% with the corresponding n-base layer and pemitter layer thickness of 0.410 µm and 0.174 µm respectively and the total device thickness of 0.65 µm. According to these results, the proposed cell demonstrates an improvement in the efficiency and a reduction of the used GaInP material. [ABSTRACT FROM AUTHOR]

Room temperature deposited aluminium-doped zinc oxide thin films on glass substrate, using pulsed-DC magnetron sputtering, have shown high optical transmittance and low electrical resistivity with high uniformity of its spatial distribution after they were exposed to a rapid thermal annealing process at 400 °C under N 2 H 2 atmosphere. It is particularly interesting to note that such an annealing process of AZO thin films for only 30 s was sufficient, on one hand to improve their optical transmittance from 73% to 86%, on the other hand to both decrease their resistivity from 1.7 × 10 −3 Ω cm to 5.1 × 10 −4 Ω cm and achieve the highest uniformity spatial distribution. To understand the mechanisms behind such improvements of the optoelectronic properties, electrical, optical, structural and morphological changes as a function of annealing time have been investigated by using hall measurement, UV–visible spectrometry, X-ray diffraction and scanning electron microscope imaging, respectively. [ABSTRACT FROM AUTHOR]

This work focuses on the modeling and optimization of a structure based on InGaP/InGaAs/InGaAsN/Ge for photovoltaic. In this study we took into consideration the concentration effect of alloys x (In) and y (N) on the strain, the bandgap, the absorption and structure efficiency. It has been shown that the concentration of indium varies the strain and the bandgap. These two parameters change considerably the yield. Also it optimized the effect of alloys on the total absorption of the structure. For a concentration of indium x = 0.40 and y = 0.03 we had a absorption coefficient which is equal to 2 × 10 6 cm −1 . We have found 50% efficiency for the multi-junction structure based on In 0.55 Ga 0.45 P/In 0.40 Ga 0.60 As/In 0.30 Ga 0.70 As 0.97 N 0.03 /Ge. To achieve a reliable high efficiency multi-junction structure, we just need to optimize the concentrations of different alloys. [ABSTRACT FROM AUTHOR]

Summary: This effort is founded on the modeling and simulation of the GaAsPN/GaP quantum dot (QD) solar cell. This quaternary alloy is one of the III‐V semiconductors, which gained importance in the recent years for optoelectronic applications. This importance comes from the fact that the quaternary GaAsPN can be a well‐grown lattice matched to GaP and Si substrates and to the bandgap that can be decreased drastically with the incorporation of nitrogen and arsenic into GaP, improving consequently the absorption and the wavelengths near the red part. These qualities make GaAsPN a good candidate for the growth on the Si substrate and low‐cost solar cell fabrication. The optical properties of GaAsPN/GaP QDs, such as strain, critical thickness, bandgap energy, the external quantum efficiency, and absorption coefficient, have been reported. The heterostructures consist of GaAs0.18P0.814N0.006 QDs separated by GaP barrier layers. The width and thickness of QDs are about 5 and 5 nm, respectively. Our results have been shown that 20 GaAs0.18P0.814N0.006/GaP QD layers produce a short‐circuit current of about 3.55 mA/cm2 and an efficiency of about 7.5%. In addition, we will be able to extend the absorption edge of a GaP solar cell from 0.48 μm to 0.5 μm for the same QD number layers inserted. The temperature effect on efficiency is considered. [ABSTRACT FROM AUTHOR]

Purpose: The SPUR (Social, Psychological, Usage and Rational) Adherence Profiling Tool is a recently developed adaptive instrument for assessing key patient-level drivers for non-adherence. This study describes the SPUR questionnaire's finalization and psychometric evaluation. Patients and Methods: Data were collected through an online survey among patients with type 2 diabetes included by general practitioners and diabetologists in France. The survey included four questionnaires, SPUR and three validated adherence measures: BMQ, MARS and ACCEPT. Item-level analysis and a partial credit model (PCM) were performed to refine the response option coding of SPUR items. The final item selection of SPUR was defined using a PCM and a principal component analysis (PCA). Construct validity, concurrent validity and known-groups validity were assessed on the final SPUR questionnaire. Results: A total of 245 patients (55% men, mean age of 63 years) completed the survey remotely and were included in this analysis. Refining response option coding allowed a better discrimination of patients on the latent trait. After item selection, a short, an intermediate, and a long form composed the final SPUR questionnaire. The short form will be used to screen patients for risk and then the other forms will allow the collection of further information to refine the risk assessment and decide the best levers for action. Results obtained were supportive of the construct validity of the forms. Their concurrent validity was demonstrated: moderate to high significant correlations were obtained with BMQ, MARS and ACCEPT scores. Their known-groups validity were shown with a logical pattern of higher scores obtained for patients considered non-adherent and significant differences between the scores obtained for patients considered adherent versus non-adherent. Conclusion: SPUR is a valid tool to evaluate the risk of non-adherence of patients, allowing effective intervention by providing insights into the respective individual reasons for lack of adherence. [ABSTRACT FROM AUTHOR]

• The lattice matching condition determination in order to obtain stable structure. • Physical and optical parameters determination at room temperature. • Emphasizing the impact of the absorption coefficient on the frequency response. • Frequency response optimization of the new pin photodiode structure. • Managing the frequency response limitations through the transparent layers. • Total frequency response calculation and highlighting its limitations. This paper reports on pin photodiode frequency response optimization based on In x Ga 1-x As 1-y N y quaternary lattice matched to GaAs. Two transparent layers are placed on p-side and n-side in order to manage the photodiode frequency response limitations. The lattice matching condition is calculated in order to obtain stable structure. The physical and optical parameters calculations are performed at room temperature showing the impact of nitrogen on the absorption coefficient. A stable structure, having 2 % of nitrogen and 6% of indium, allows to achieve a cutoff frequency of about 116 GHz and a capacitance of 5.21fF while the quantum efficiency is 41.59% for a depletion region thickness of about 0.55 µm. However, in case of depletion region thickness of about 0.625 µm, the cutoff frequency degrades to 98 GHz while the capacitance diminishes to 4.58fF and the quantum efficiency increases to 51.56%. In addition, a comparative study with literature results has been carried out in order to show the advantages of the proposed photodiode. This comparison affirms that the proposed photodiode based on InGaAsN lattice matched to GaAs exhibits high-speed photo-detection. This work allowed us to obtain a p-i-n photodiode with stable structure suitable for photo-detection at 1.15 µm. [ABSTRACT FROM AUTHOR]

In this paper, the CuInGaSe 2 based solar cell optimization has been established. We have simulated the structural strain effect. The effect of gallium concentration on the optical properties and the quantum external efficiency EQE was investigated. We also optimized the concentration x at low defect densities. The optimal gallium concentration is 0.30. We obtained an efficiency of the CuIn 0.70 Ga 0.30 Se 2 absorber solar cell around 24% with a strain ɛ = 0.64% and material defects densities equal to 1.2x1015cm−3. This work has been validated by theoretical and experimental studies. This study allows us to find a compromise between concentration x and defect concentrations in order to improve the performance and high efficiency of the solar cell. • The effect of structural deformation has been studied and simulated. • The effect of gallium on the optical properties and EQE was investigated. • We optimized the x concentration at low defect concentrations. • An efficiency of the solar cell which is equal to 24% with ɛ = 0.6% was obtained. • This work is validated by a theoretical and experimental study. [ABSTRACT FROM AUTHOR]

This study aims to investigate the different optical properties of the ZnSnN 2 absorber layer such as absorption, reflection and transmission coefficients. The effects of the ZnSnN 2 absorber layer thickness, temperature,and defect density on electrical parameters such as short circuit current density, open circuit voltage, fill factor and efficiency have also been studied in detail. These factors play an important role in the performance of the ZnO/CdS/ZnSnN 2 /Si/Mo structure. The highest efficiency of about 23.32 % is achieved without defects in the ZnSnN 2 absorber layer, under the 1-sun AM1.5 solar spectrum, by applying the flat band condition and considering the strain values of 0.37 % (ZnSnN 2 /Cds) and 7.17 % (ZnSnN 2 /Si). In addition to high efficiency, the ZnSnN 2 has a high absorption coefficient. This device will play a crucial role in optoelectronic applications. This structure is a promising candidate for low cost and high efficiency photovoltaic technology. [ABSTRACT FROM AUTHOR]

Candida albicans mannan consists of a large repertoire of oligomannosides with different types of mannose linkages and chain lengths, which act as individual epitopes with more or less overlapping antibody specificities. Although anti-C. albicans mannan antibody levels are monitored for diagnostic purposes nothing is known about the qualitative distribution of these antibodies in terms of epitope specificity. We addressed this question using a bank of previously synthesized biotin sulfone tagged oligomannosides (BSTOs) of α and β anomery complemented with a synthetic β-mannotriose described as a protective epitope. The reactivity of these BSTOs was analyzed with IgM isotype monoclonal antibodies (MAbs) of known specificity, polyclonal sera from patients colonized or infected with C. albicans, and mannose binding lectin (MBL). Surface plasmon resonance (SPR) and multiple analyte profiling (MAP) were used. Both methods confirmed the usual reactivity of MAbs against either α or β linkages, excepted for MAb B6.1 (protective epitope) reacting with β-Man whereas the corresponding BSTO reacted with anti-α-Man. These results were confirmed in western blots with native C. albicans antigens. Using patients' sera in MAP, a significant correlation was observed between the detection of anti-mannan antibodies recognizing β- and α-Man epitopes and detection of antibodies against β-linked mannotriose suggesting that this epitope also reacts with human polyclonal antibodies of both specificities. By contrast, the reactivity of human sera with other α- and β-linked BSTOs clearly differed according to their colonized or infected status. In these cases, the establishment of an α/β ratio was extremely discriminant. Finally SPR with MBL, an important lectin of innate immunity to C. albicans, classically known to interact with α-mannose, also interacted in an unexpected way with the protective epitope. These cumulative data suggest that structure/activity investigations of the finely tuned C. albicans anti-mannose immune response are worthwhile to increase our basic knowledge and for translation in medicine. [ABSTRACT FROM AUTHOR]

This paper focuses on the simulation and optimization of electrical and structural properties of high efficiency InGaP/InGaAs/Ge triple junction solar cells that incorporate In 0.7 Ga 0.3 As quantum dots with in the GaAs middle cell material. Current density-voltage (J-V) , external quantum efficiency (EQE) and capacitance-voltage (C-V) characteristics have been simulated and discussed. Results show that 30 pairs of In 0.70 Ga 0.30 As (QD)/GaAs (barrier) in the middle cell provide a relative enhancement of 13% in EQE in the 900–1000 nm wavelength range. This leads to a short-circuit current of 20 mA/cm2, an open circuit voltage of 2.3 V, a fill factor of 81.73%, and a conversion efficiency of 39.03%. The C-V revealed that a relatively high number of interfacial states are present in the 3-J cell structure including the QD layers, which decreases the open circuit voltage. In this study we benefited 18% of relative efficiency. • This paper focuses on the simulation and optimization of electrical and structural properties. • InGaP/GaAs/Ge triple junction (3-J) solar cell incorporated by variable number of In 0.7 Ge 0.3 As. • In this goal, current density-voltage, external quantum efficiency and the capacitance-voltage. • This leads to a short-circuit current of 19.97 mA/cm2, V OC = 2.3 V, FF = 81.73%, η = 39.03%. • The C-V revealed that a relatively high number can be present in the 3-J included the QD layers. [ABSTRACT FROM AUTHOR]

This article introduces two-way broadband air-filled substrate integrated waveguide (AFSIW) isolated power dividers/combiners based on surface mounted absorbing materials. The proposed structures take advantage of the AFSIW multilayer feature. The absorber implementation is found highly tolerant of variations in dimensions and positioning. Three different power dividers/combiners topologies are analyzed theoretically, simulatively, and experimentally. The measurement results validate the broadband responses of the fabricated Ka-band demonstrators. The proposed power dividers/combiners are intended to exploit high-power AFSIW system on substrate (up to few hundred watts). [ABSTRACT FROM AUTHOR]

In this paper, we describe a novel fabrication method of a microfluidic integrated surface plasmon resonance (SPR) gold chip based on a (3-mercaptopropyl) trimethoxy silane (MPTMS) self-assembled monolayer. This monolayer was formed at the surface of a microfluidic chip made of polydimethylsiloxane (PDMS). Its presence was confirmed by contact angle and Fourier transform infrared spectroscopy measurements on the modified PDMS surface. A basic, but nevertheless appropriate, 4-channel microfluidic system was made on PDMS and reported on a gold SPR sensor. Sealing tests were carried-out by injecting continuous flows of solutions under gradient pressure up to 1.8 bar. Bonding strength of chemical and corona binding were measured and compared. The test of the integrated microfluidic SPR sensor on an SPR bench validated its functionality and proved as well that no leakage is observed between the different microfluidic channels. [ABSTRACT FROM AUTHOR]

A combination of a Copper Indium Gallium Selenide (CIGS) and Silicon (Si) layer has been recognized as an excellent choice for producing heterojunction based solar cells with improved efficiency and low cost processing techniques. The quaternary compound CIGS and silicon (Si) regions exhibit a lattice mismatch of about 5%, which induces a strain and impacts the electronic characteristics of the CIGS/Si heterojunction solar cell. A new viewpoint suggests the integration of a silicon germanium (Si 1-y Ge y) layer in the CIGS/Si region to reduce the impact of lattice mismatch. The objective of this study is to investigate how different gallium and germanium concentrations (x Ga and y Ge) affect the following factors: lattice mismatch (ε) , critical thickness (h c) and absorption coefficient (α)of CIGS/SiGe based solar cells. It also aims to analyze how these concentrations impact the primary parameters used to evaluate solar cell performance such as external quantum efficiency, short circuit current density, fill factor, open circuit voltage and conversion efficiency. The simulation results agree well with the existing theoretical and experimental literature data, confirming the suitability of the physical characteristics employed in this numerical study. By tuning the concentrations of Gallium and Germanium, it is feasible to attain an efficiency of 24% owing to the lattice compensation phenomenon in Si 1-y Ge y layers. These findings hold significant implications for the development and advancement of solar cell technology, as well as for enhancing their conversion efficiency and commercialization. • A strain-compensated CIGS/Si structure was achieved by adding SiGe layer. • The incorporation of SiGe improves the absorbance and EQE of the CIGS solar cell. • The improvement of the solar performances of the CIGS is ensured by the SiGe layer. • Optimizing Ga, Ge concentrations makes it possible to achieve an efficiency of 24%. [ABSTRACT FROM AUTHOR]

Abstract This work investigates the influence of the ion source (Au+ and Si+2 ions) of liquid metal alloy source-focused ion beam (LMAIS/FIB) on the nanopattering. Two sets of SiO 2 /Si nanopatterns with a width of 450 nm on Silicon on insulator (SOI) substrate are fabricated by 30 keV Au+ and Si+2 ions, respectively. To study this effect, the sputtering yield is calculated using the volume loss method from atomic force microscopy (AFM) profiles obtained for each set. The results of the sputtering yield were compared with theoretical results calculated from Yamamura model for normal incidence for validation. The comparison showed a good agreement between the two results with a relative difference of about 5.3% obtained using Si+2 ions. Highlights • The effect of AuSi LMAIS/FIB ions on nanomilling is investigated experimentally. • This effect has been shown through the study of sputtering yield. • The comparison has shown that Au+ ions are better for stable nanopatterns. • Our experimental results are in good agreement with calculated results. [ABSTRACT FROM AUTHOR]

In this work we report a modeling and optimization of a novel core (p-GaN)-multishell (i-In x Ga 1-x N/i-GaN/n-Al 0.1 Ga 0.9 N/n-GaN) coaxial NWs with a total length of about 3 μm and a radius of 0.19 μm. The variation of Indium composition in the i-In x Ga 1-x N active layer shows that x = 15% is the optimal composition that gives a good short circuit current and efficiency of about 2.24 mA/cm 2 and 2.93%, respectively. Beyond x = 35% the structure starts to present deteriorations. Moreover, the optimal x composition founded provides a gain of about 12.9% of EQE in the mid-infrared part. The study of the variation of the total current density along the nanowire demonstrates that the maximum of this latter is located in AlGaN cladding shell layer and at the interfaces between the i-region and AlGaN cladding shell layer. In other hand, our results show that our structure presents an optimal efficiency of about 3.5% at a temperature of 275 K with the same AM1.5G solar spectrum. [ABSTRACT FROM AUTHOR]

Aluminum doped-zinc oxide (AZO) thin films were prepared on glass substrate by radio-frequency (RF) sputtering at room temperature. The sheet resistance, R sh [Ω] the resistivity, ρ [Ω·cm] and the 1/ f noise were studied as a function of thickness, t from 50 nm to 450 nm. The eddy current characterized the homogeneity of AZO thin films. The surface morphology has been analysed by atomic force microscopy (AFM). The 1/ f noise is normalized with respect to the bias, frequency and unit area, and C us is proportional to the sheet resistance R sh . Two configurations were used to characterize material and contact noise. The pressure effect of four point-probe on the material and the contact noise were also investigated. Our results show that the homogeneity of the samples increases as the film thickness increases and the resistivity decreases with increasing thickness and reaches the lowest value of 1 × 10 − 3 Ω cm at 450 nm. The average grain size and the root-mean-square roughness increases with rising thickness. The ratio K = C us / R sh is proportional to t 2 , which indicates that the mobility and the noise parameter α H shrink with the shrinkage of the thickness. [ABSTRACT FROM AUTHOR]

In this work we propose a modeling and simulation of core/shell p-i-n Si/Si 0.2 Ge 0.8 nanowire for photovoltaic. In the first step of this work, we have compared the core/shell p-i-n homojunction Si and heterojunction Si/Si 0.2 Ge 0.8 Nanowire (NW) solar cell having a length of 3 μm and a radius of 0.19 μm, by studying their current-voltage and external quantum efficiency (EQE). Our results have shown that blending Silicon with 80% of Germanium enhances relatively the short circuit current and efficiency by 3.04% and 8.48% respectively. In other hand, the absorption edge of Silicon NW has extended from 1100 nm to 1200 nm, with a gain of EQE of 15% obtained in this range. In the second part, we have tried to optimize the Si/Si 0.2 Ge 0.8 structure, by varying their radius and length. The corresponding results have indicated that a radius of 0.28 μm and a length of 10 μm are the optimal geometric parameters for any optimization of such structure. [ABSTRACT FROM AUTHOR]

The present study reports the impact of structural parameters on optoelectronic properties of InGasb/GaSb based quantum well structures (Qws). The laser diodes are designed to operate at 2.3 μm at 300 K. Numerical calculations of the emission wavelength, optical and modal gain of TE mode in InGaSb/GaSb laser diode structure have been carried out for various well material compositions, well thickness, number of quantum wells and temperature. The optical confinement factor and threshold current density are also simulated and reported. The calculations were performed using the 8-bands k.p model. For an injected carrier concentration of 1.56 × 1018 cm−3 at 300 K, peak gain value of the order of 1400 cm−1 is reached and a modal gain of 94 cm−1 can be obtained. A threshold current density around 3 kA/cm2, is expected to be obtained through optical losses of about 50 cm−1. The results show that InGaSb/GaSb quantum wells are appropriate for mid-infrared lasers operating at 300 K. • Type-I InGaSb/GaSb lasers, emitting at 2.3 μm are studied. • Optical/modal gain, confinement factor and the threshold current density are investigated. • A modal gain of 94 cm−1 can be reached at room temperature. • J th of 3 kA/cm2 is obtained under optical losses of about 50 cm−1 and T 0 =57 K at RT. • InGaSb/GaSb QWs are appropriate for mid-infrared lasers operating at T=300 K. [ABSTRACT FROM AUTHOR]

The electrical properties of InAsP/Si quantum dot solar cell (QDSC) are numerically studied and analyzed in this paper. Many effects like number of quantum dot (QD) layers inserted and Arsenic content of InAs x P 1-x on photovoltaic properties such as current density-voltage J-V and the external quantum efficiency (EQE) are investigated. Our results have been shown that the optimal Arsenic content is 0.6. With 30 InAsP/Si QDs layers, relative enhancements of about 7% and 6.70% of short-circuit current and efficiency are achieved, respectively. Otherwise, the absorption range edge of low energy photons was extended from 1120 to 1200 nm. This reveals that introduction of QDs in the intrinsic region of p -i- n Silicon (Si) solar cell enhances significantly the device characteristics beyond what has been reported for conventional semiconductor-based solar cells. [ABSTRACT FROM AUTHOR]

In this investigation, the mechanical properties of the different layers composing a CuIn 1 − x Ga x Se 2 (CIGS) based solar cell were studied. Magnetron sputtering technique was used for the deposition of these layers except for the cadmium sulphide (CdS) layer which was deposited using chemical bath deposition process. We performed several indentation tests on the individual layers, i.e. molybdenum (Mo) back contact layer, CIGS absorber layer, CdS and alternative zinc sulphide oxide (ZnOS) buffer layers, and zinc oxide (ZnO)-AZO (aluminium-doped zinc oxide) transparent window layer; all were deposited on glass substrates. We report the values of the hardness ( H ) and of the Young's modulus ( E ) for each material, using indentation tests and an analytical model. The Mo layer remained the hardest and the most rigid, with H = 8.7 GPa and E = 185 GPa, while the CIGS layer has shown poor mechanical properties with H = 3 GPa and E = 58 GPa. On the other hand, the observed similarity in mechanical properties of the ZnO and ZnOS layers might be attributed to the similarity of their microstructures. [ABSTRACT FROM AUTHOR]

In recent years, the development of quantum well solar cells QWSCs (Quantum Well Solar Cells) has generated a great deal of interest. These configurations have shown good promise to optimize the low conversion efficiency of conventional solar cells because of the high rate of absorption losses present in them. In this work, we are interested in modeling and simulation of two different structures of solar cells, a simple solar cell based on silicon Si and a quantum well solar cell SiGe/Si. When a solar cell is compared to 80 quantum well layers of Si 0.8 Ge 0.2 with a pin solar cell based on Si. The short circuit current J sc increases from 23.55 to 37.48 mA/cm 2 with a relative increase of 59.15% found. In addition, the limit of the absorption band of the lower energy photons extends from 1100 nm to 2000 nm. [ABSTRACT FROM AUTHOR]

A novel strategy to achieve 3D pattern transfer into silicon in a single step without using lithography is presented. Etching is performed electrochemically in HF media by contacting silicon with a positively biased, patterned, metal electrode. Dissolution is localized at the Si/metal contacts and patterning is obtained as the electrode digs into the substrate. Previous attempts at imprinting Si using bulk metal electrodes have been limited by electrolyte blockage. Here, the problem is solved by using, for the first time, a nanoporous metal electrode that allows the electrolyte to access the entire Si/metal interface, irrespective of the electrode dimensions. As a proof of concept, imprinting of well-defined arrays of inverted pyramids has been performed with sub-micrometer spatial resolution over 1 mm 2 using a nanoporous gold electrode of the complementary shape. Under a polarization of + 0.3 V/SME in 5 M HF, the etch rate is ~ 0.5 μm min − 1 . The pyramidal pattern is imprinted independently of the Si crystallographic orientation. This maskless imprinting technique opens new opportunities in the fabrication of Si microstructures. [ABSTRACT FROM AUTHOR]

In this aim, we were interested in the optimization and simulation of pin-In 1−x Ga x N structure and InGaN multi quantum well structures for photovoltaic applications. This ternary alloy which is an III–V semiconductor presents important characteristics especially its gap energy, thus, the increase of the photons absorption of wavelengths. It has been shown that the increase in indium concentration increases the current density J sc and the maximum output power. In return, the V oc decreases consequently. For In 0.50 Ga 0.50 N structure we observed that the current density and the maximum power are respectively around 19.50 mA/cm 2 and 27.50 mW/cm 2 with a ratio of 21.65 mA/cm 2 . Also it is shown that the incorporation of the quantum well in the active region results in an increase of J sc and P max but V oc remains unchanged. The incorporation of 50 quantum well structure in the In 0.50 Ga 0.50 N gives 22 mA/cm 2 of the current density and 32 mW/cm 2 of the maximum output power. The use of the structure based on In 0.50 Ga 0.50 N (MQW) induces an efficiency of 32%. We deduced that the relative efficiency is improved by 10.9%. [ABSTRACT FROM AUTHOR]

This paper proposes a method of modeling and simulation of InAs/GaAs-based quantum dots (QDs) for solar cell. The main objective is to find the growth parameters in order to produce an optimal double heterostructure using two semiconductor materials InAs and GaAs. We are interested in particular on the impact of the growth control parameters on the physical properties of the two-dimensional InAs mono-layer. We report here a complete but non-exhaustive analysis of the electronic states of the InAs based QDs layers grown on a GaAs substrate. In this work, the reader will find the modeling and the simulation results for both rectangular and elliptical geometries of InAs QDs. In the first part of this work, we provided the change of the electronic transition energy as a function of quantum dots’ radius whilst the second one concerns the absorption coefficient as a function of the incident photon wavelength. The curves we have obtained indicate clearly that the geometrical shape of the InAs QDs does significantly modify the various parameters above. We could therefore confirm that the more appropriate geometry is the elliptical one because of the higher performances. [ABSTRACT FROM AUTHOR]

In this study, we experimentally elaborated Copper- and Indium-doped Zinc Oxide (Cu: ZnO and In: ZnO) thin films at different temperatures (T 1 = 480 °C and T 2 = 520 °C), the doping ratio were varied between 0% and 8%. Using a low cost solution-based chemical deposition, we have developed a ZnO thin film deposition process that offers fine-control of the surface morphology. It consists in spraying a volatile compound of the material to be deposited on a substrate maintained at high temperature to cause a chemical reaction in order to form at least one solid product. Therefore, the proposed ZnO doped layer is highly promising for applications for the next-generation solar cells. [ABSTRACT FROM AUTHOR]

Back-to-back GCPW-MS-GCPW (Grounded Coplanar Waveguide-Microstrip lines) transitions realized on benzocyclobutene polymer thin films (20 μm) and using copper metallization are presented in this article. The achieved experimental bandwidth is 82 GHz with a remarkably lower cutoff frequency of only 1.5 GHz and insertion loss of 0.5 dB. This performance is obtained without neither making via holes in the substrate nor patterning the bottom ground plane. These transitions make easier and faster manufacturing and characterization, by means of coplanar probes, of microwave devices realized from materials in thin film and whose driving electrode is a MS line. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2041-2045, 2015 [ABSTRACT FROM AUTHOR]

This work reports on theoretical studies on the GaInNAs material properties (bandgap, lattice mismatch, absorption coefficient) as grown on GaAs substrate. The Band Anti-Crossing (BAC) k ⋅ p 8 × 8 model has been used to determine the influence of indium and nitrogen concentrations on the position of conduction and valence bands. The incorporation of nitrogen at a level lower than 5% causes the split of the conduction band. For indium and nitrogen concentrations of 38% and 3.5%, respectively, the strained bandgap energy is 0.70 eV and the absorption coefficient of indium and nitrogen-rich compounds increases significantly. [ABSTRACT FROM AUTHOR]

In this paper, we report a theoretical investigation of bandgap properties of GaAsNBi based materials on GaAs substrates. We look at the influence of nitrogen (N) and bismuth (Bi) concentrations on the position of conduction and valence bands; and we show that a split of the conduction band can take place with the incorporation of N at 5% under level, while a split of the valence band of both heavy and light holes sub-bands takes place after the incorporation of Bi at 14% under level. In order to compute the transition energies, we used the VBCA k.p 16×16 model. The N and Bi concentrations effects as well as the lattice mismatch value have also been taken into account. For a couple of N and Bi concentrations of 3% and 6%, we found strained gap energy around 0.68 eV. Furthermore, we have also shown that the absorption coefficient increases significantly when the N and Bi concentrations increase. [ABSTRACT FROM AUTHOR]

In this work, two process simplifications for n-type PERT (passivated emitter rear totally diffused) bifacial solar cells are investigated. Both are based on a single thermal treatment for elaborating boron and phosphorus doped regions aiming at reducing the number of high temperature steps of standard process. The first simplification shows a mixed co-diffusion from a gaseous source of phosphorus and a boron doped dielectric layer elaborated by low frequency plasma enhanced chemical vapor deposition (PECVD). The second exhibits two independent ion implantations, followed by a co-anneal/activation step. In both cases, implied open-circuit voltages are similar to standard process (~660–670 mV) and emitters allow good contacting by screen-printing ( ρ c =3.0–5.0 mΩ cm 2 ). PERT cells resulting from these processes show very promising performances with efficiency up to 19.7% on industrial 156×156 mm 2 pseudo square Cz wafers. [ABSTRACT FROM AUTHOR]

Pyramidal textures are commonly used to reduce reflections from silicon solar cells and improve light absorption by light trapping. They are generally modelled or characterised under normal incidence. In this work, a monolayer 3D ray tracing program taking into account the polarisation of light have been developed, validated and used to compute the directional-hemispherical reflectance versus the azimuth and incidence angles for both regular upright pyramids and inverted ones, with (1 1 1) facets. Results are given for a wavelength of 0.7 μ m . They show that this reflectance is not minimal at normal incidence but for an incidence angle near 20 ° and that upright pyramids can have a lower hemispherical reflectance than inverted ones for incidence angles in the middle range. The bihemispherical reflectance is 19.6% for regular upright pyramids and 20.7% for inverted ones. The effect of the pyramids aspect ratio on the hemispherical reflectance at normal incidence is also studied. This reflectance decreases with the aspect ratio of both textures. Above an aspect ratio of 0.51, inverted pyramids have a lower hemispherical reflectance. But their bihemispherical reflectance is lower only for aspect ratios below 0.23. [ABSTRACT FROM AUTHOR]

In this work, we have studied solar cells based on AlGaInAs/InP quaternary structure to describe the behavior of electronics components. To this end, we have developed a simulation program to study the gallium Ga and aluminum Al concentrations effect on respectively the lattice mismatch, the band gap energy, the absorption and the power delivered by the solar cell. This study allows us to compare between simulation and experimental results, once the cell parameters are optimized by a judicious choice of concentrations. This work allows us either to use nanotechnologies for solar cells. [ABSTRACT FROM AUTHOR]